The present invention relates to lightweight anchor. Various types of anchors have been devised, each having its good points and its bad ones:
One known type of anchor, when stuck between rocks or in an obstacle such as a crack or a cleft of seabed, has relied on some force excerted by its user on board a ship in recovering the anchor from the bottom. However, this type of anchor has been either a too complicated one with too many moving parts to be readily manipulated by its user, or a too costly one, or both. By `some force` is meant either one of these:
1. The gravity of a heavy metal weight (often with a guide attachment to it) which slides down along the rope and hits the stuck anchor at its small protuberance mechanically triggering its release from the obstacle. PA1 2. A human force tugging the anchor rope and great enough to detach the anchor from the obstacle. PA1 3. A human force tugging an additional rope to the regular anchor rope, the additional rope being attached to a different part of the anchor from the part to which the regular anchor rope is attached.
Another known type of anchor, commonly called a stocked anchor, has a stock which occupies an ample space on board a ship or on dry land, sitting unstable. In order to overcome this demerit, a type with a retractable stock has been devised; however, this anchor with a retractable stock has been more costly than the conventional one with an unretractable stock.
The type of anchor designed to have a great biting force even when the bottom material is mud or sand has been apt to bring up the mud or the sand of the bottom, requiring much time and backbreaking labor of holding the anchor near the water surface and shaking it many times until the mud or the sand is washed off.
And still another type of anchor such as Danforth anchor uses a mechanism of a swinging fluke which hinges on a pivot on one end of a shank. This mechanism enables this type of anchor to regain its biting force when the anchor turns upside down and starts to drag; this ability to regain biting force is one of its good merits. However, this anchor also has a demerit: the user of this often gets his or her finger pinched in between the shank and the swinging fluke.
Yet another type of anchor is a stockless, single-fluke anchor with a movable line connection; the one disclosed in U.S. Pat. No. 4,523,539 and also the one disclosed in U.S. Pat. No. 5,188,055 belong to this type. However, even the anchor of this type faces a problem: if the anchor reaches bottom in such a posture that the aspect of the anchor's fluke is adverse to the tugging force of the anchor and if the point of the anchor rope's engagement to the anchor shank happens to be too close to the base part of the shank, it will not have a good hold onto the bottom; it most probably will back out and drag on. With this type of anchor the tendency to drag is more marked when the bottom material is, like sand, fairly flat and firm.
The object of the invention is to provide a lightweight anchor which can be easily fabricated, put into practical use, and readily handled, hence avoiding the problems mentioned above.